The invention relates to catalysts or catalyst precursors for forming disubstituted .alpha.-olefin dimers from a 1-olefin reactant.
Prior to the present invention, there have been no known homegeneous catalysts for converting a terminal olefin selectively to a disubstituted .alpha.-olefin dimer at room temperature or above. Known homogeneous dimerization catalysts readily isomerize the initially formed dimer to the thermodynamically more stable internal olefin. It is also known that heterogeneous catalysts such as chromocene on alumina or silica produce 1-butene from ethylene. In addition, other selected dimerization reactions are known. However, these reactions generally are successful for only one olefin, e.g., the use of KC.sub.8 to dimerize propylene selectively to 4-methyl-1-pentene.
Accordingly, it would be desirable to provide a homogeneous catalyst system for forming primarily one or both disubstituted .alpha.-olefin dimers which can be used with any one of a plurality of unsubstituted or substituted 1-olefin feed compositions.